1. Filed of the Invention
The present invention relates to a percussion tool, such as a hand-held drill or a chisel tool, and including a header displaceable in the tool chuck, a damping member for damping rebounds of the header and cooperating with a stop surface which is provided at a rear, with respect to the operational direction of the percussion tool, end of the header, with the damping member including arranged one after another a stop disc, an elastic ring and a transmission element, and a percussion mechanism including a guide cylinder defining a stop for the damping member.
2. Description of the Prior Art
German document DE-OS 41 35 240 discloses a percussion tool such as a drill or a chisel tool having a percussion mechanism with a guide cylinder and a tool chuck. The guide cylinder receives a percussion piston, which is driven by a swash plate mechanism, and a float piston driven by the percussion piston. An axially displaceable header is located in central bore of the chuck in its rear, with respect to an operational direction, end region. During the operation of the percussion tool, the header cooperates with a shank of a tool inserted in the tool chuck at the front end surface of the chuck. The portion of the header remote from the tool shank has a cylindrical cross-section and a reduced diameter. The rear cylindrical portion of the header extends through a damping member provided between a stop, which is formed on the guide cylinder of the percussion mechanism, and the stop shoulder formed at the rear end of the header. The damping member serves for damping rebounds of the header and is formed of a stop disc cooperating with the header, a transmission element supported against a stop provided on the guide cylinder of the percussion mechanism, and an elastic ring arranged between the stop disc and the transmission element. The stop on the guide cylinder is formed by a locking element formed as a snap ring which projects into an annular indentation formed on the inner side of the guide cylinder.
A serious drawback of the prior art percussion tool consists in difficulties associated with mounting of the damping member because all elements of the damping member need be separately installed in the guide cylinder and aligned there.
The subsequent insertion and fixing of the snap ring with an appropriate tool requires a lot of skill and a high concentration from a worker. Because the mounting of the damping member is very labor-consuming, it requires a lot of time.
Accordingly, an object of the present invention is to provide a percussion tool such as a drill or a chisel tool in which mounting and dismounting of the damping member can be effected rapidly, simply and economically.